With the advancement of integrated circuit technology, the number of transistors within an integrated circuit has increased exponentially. This increased concentration of transistors has led to a super hot core within the integrated circuit die (die) during integrated circuit operation. With this super hot core, good thermal management is crucial to prevent integrated circuit performance degradation. Typically, various thermal management techniques are employed to ensure that the integrated circuit core temperature is maintained in an acceptable range.
Often times, thermal management of the integrated circuit requires the use of a thermal dissipation device, such as a heatsink to dissipate heat generated by the integrated circuit. A heatsink includes a mass of material thermally coupled to the integrated circuit to conduct thermal energy away from the high-temperature region of the integrated circuit to a low-temperature region of the heatsink. The thermal energy can then be dissipated from a surface of the heatsink to the environment surrounding the heatsink primarily by convection.
An integrated heat spreader (IHS) is typically placed between the integrated circuit and the heatsink. When two solids are placed together, in addition to their respective bulk thermal resistances, there will be thermal interfacial contact resistance between the solids due to the inherent irregularities of the contacting surfaces. For this reason, a first layer of thermal interface material (TIM) is often placed between the integrated heat spreader and the integrated circuit to better wet the interfaces to minimize thermal contact resistance between the integrated circuit and the integrated heat spreader. Likewise a second layer of thermal interface material is placed between the integrated heat spreader and the heatsink. Unfortunately, no matter how well the contact is, there will still be gaps in the interfaces. The current polymer-based and solder-based thermal interface material technology is limited in its ability to meet the heat transfer needs of the ever advancing concentration of transistors in today's integrated circuit.
One attempt to improve on the polymer-based and solder-based thermal interface material technology is the development of thin die thin TIM (TDTT) with improved material bulk thermal conductivity.